Work Issue

Open an isolated git worktree, implement one open GitHub issue, then ship it. The leading word is worktree-first: never implement on the main checkout. PR mechanics (push, PR creation, merge) are delegated to arc-git-pr-check.

Load WORKTREE.md before creating the worktree. Load arc-conventional-commits before committing for commit type and message format.

Orchestrator route guidance

Standalone behavior remains unchanged: without an orchestrator, --ship merge is the default and arc-git-pr-check retains all of its ship modes. Under an orchestrator, omitted ship mode means PR-first --ship pr; honor an explicit caller request for --ship auto or --ship merge. The parent creates and owns the worktree, decides the approach, inspects worker evidence, and retains review judgment and approval.